General Surgery Coding Alert

Reader Questions:

Cut the Fog of Calculating Anesthesia Charges

Published on Mon Feb 19, 2024

Question: Could you clarify the process for determining and documenting charges for anesthesia services? When you key in charges for anesthesia, are you keying total time in minutes or units plus base units, or is it insurance plan specific?

AAPC Forum Participant

Answer: Reporting requirements for anesthesia time are insurance plan-specific; most require total minutes, but a few ask for total units. Check with your payer if you’re unsure which is preferred and cannot find a policy.

Keying in time will depend on your software. You should enter the anesthesia time exactly as documented — software systems usually have parameters in place that determine whether to round time up or down and how to report to each payer. However, not all anesthesia software is sophisticated enough to follow the many payer requirements. When coders enter anesthesia time for charges, typically, the system is set to round time up to the nearest whole unit.

Do this: The best way to report is to provide exact minutes for total time and include anesthesia start and stop times on the claim.

Correctly coding and reporting charges involves the following criteria:

The difficulty of the procedure performed (base units)
Time (time units)
Modifying factors (modifying units)

The general formula for calculating anesthesia charges is:

(Base units + Time units + Modifying units) x Conversion factor = Anesthesia charge

Note: Modifying units includes consideration of emergencies and the patient’s changing health conditions.

Also, you should not report base units separately on the claim. Base units are determined by the difficulty of the anesthesia procedure and calculated by payers, typically using either the Centers for Medicare & Medicaid Services (CMS) or the American Society of Anesthesiologists (ASA) base values.